1. Field of the Invention
The present invention relates to improvements in a shift lever assembly operatively linked with a transmission, in particular for an automotive vehicle, which includes a gear shift lever of a floor shift type manipulated for operating the transmission.
2. Discussion of the Related Art
A typical example of a generally known shift lever assembly of a floor shift type is disclosed in Japanese Utility Model Application published in 1984 as Laid-Open Publication 59-180922, wherein a shift lever is universally supported at its spherical coupling portion by a support structure which consists of two halves in the form of a pair of support sheets whose adjoining surfaces lie in a horizontal plane. The support structure permits the shift lever to be pivoted about the spherical coupling portion in two mutually perpendicular operating planes. Pivotal movements of the shift lever in these two operating planes respectively cause two different gear shifting operations of a transmission with which the shift lever assembly is operatively linked. Another form of a known shift lever assembly is shown in FIG. 13, wherein a shift lever 29 is supported at its spherical coupling portion 30 by a support structure similar to that described above; that is, by a pair of support sheets 32, 33 which are joined together at their horizontal adjoining surfaces. These two support sheets 32, 33 are housed in a retainer cap 31 and are thereby held in position by the retainer cap 31. This retainer cap 31 is fixed to a frame of the shift lever assembly.
However, the shift lever assembly of FIG. 13 tends to have an accumulative dimensional error of the two support sheets 32, 33 and the retainer cap 31, which may result in undesirable displacements of the support sheets relative to each other and to the retainer cap 31 in the vertical direction, upon operation of the shift lever 29. As a result, the point of pivot of the shift lever is fluctuated, and the holding pressure of the support structure acting on the spherical coupling portion of the shift lever is changed, whereby the operating force of the shift lever is accordingly varied. To deal with this problem, the use of an elastic shim 34 as illustrated in FIG. 13 has been proposed to compensate for a possible variation in the relative dimensional error of the components. However, this solution increase the number of the components of the shift lever assembly, and makes it difficult to assemble the shift lever assembly.
Another form of a shift lever assembly of a floor shift type is illustrated in FIG. 14, wherein the support structure for supporting the shift lever 29 at its spherical coupling portion 30 is held in position on a support frame 35 such that the two support sheets are held in position via an elastic shim or cushion within a retainer cap 36 fixed to the frame 35. As previously described the shift lever 29 is supported pivotally in two mutually perpendicular operating planes, so that the shift lever 29 may have a first and a second pivotal movement about its spherical coupling portion in the respective first and second operating planes. The second pivotal movement is imparted to a bellcrank 37 which is pivotally supported by a support shaft 38. This support shaft 38 for the bellcrank 37 is supported by a retainer bracket 39 which is bolted to the upper surface of the support frame 35. The first pivotal movement is limited by stop members 40 which are welded or otherwise fixed to the appropriate portions of the support frame 35.
In the thus constructed shift lever assembly of FIG. 14, the shift lever 29 and the bellcrank 37 are supported by separate members secured to the support frame 35 independently of each other. Namely, the shift lever 29 is universally supported by the retainer cap 36 secured to the frame 35, while the bellcrank 37 is pivotally supported by the support shaft 38 fixed to the retainer bracket 39, and so secured to the frame 35. Therefore, the bellcrank 37 and the shift lever 29 which are linked with each other tend to have a variation in their relative positional relation. Further, a possible error in position of the stop members 40 relative to the support frame 35 causes a positioning error of the shift lever 29 at the opposite ends of its first pivotal movement. In other words, it is necessary to position the retainer bracket 35 (support shaft 38) and the stop members 40 relative to the support frame 35, so as to achieve accurate positioning of the bellcrank relative to the shift lever 29. However, the use of these retainer bracket 35, stop members 40, etc. in addition to the retainer cap 36 increases the number of the components of the shift lever assembly, leading to increased difficulty and cost of manufacture of the shift lever assembly.